What is WCDMA?
While no one can predict the future, it is certain that the way the world communicates will be vastly different from now; not least the speed of mobile and the accessibility of mobile multimedia.
Wideband Code Division Multiple Access (WCDMA) – a 3rd-generation mobile services platform – is based on modern, layered network-protocol structure, similar to the protocol structure used in GSM networks. This will greatly facilitate the development of new wireless wideband multimedia applications, allowing operators to respond in a competitive market and in turn providing advanced services for users.
Delivering wideband multimedia services will require additional performance compared with today's wireless standards. WCDMA fully supports both packet- and circuit-switched communications such as Internet browsing and traditional landline telephone services respectively.
WCDMA should not be confused with narrowband CDMA. Based on extensive research conducted between 1989 and 1997, WCDMA is a completely new technology targeting true 3G requirements. WCDMA is able to meet all the requirements outlined by the ITU, delivering high-speed data very efficiently, with high-quality sound and video services.
From the start, WCDMA has been designed for high-speed data services and, more particularly, internet-based packet-data offering up to 2 Mbps in stationary or office environments, and up to 384 kbps in wide area or mobile environments.
It has been developed and optimized with no requirements on backward compatibility with second-generation technology in the radio base station infrastructure-level WCDMA makes efficient use of radio spectrum to provide considerably more capacity and coverage than current air interfaces.
WCDMA incorporates the results of leading-edge research. The R&D yielded an optimized technology capable of delivering "mission-critical" coverage and capacity of 3rd generation mobile communications. In terms of technical superiority, therefore, WCDMA represents a significant advance over competing technologies.
The WCDMA concept, for example, is based on a completely new channel structure for all layers (L1-L3) built on technology like packet-data channels and service multiplexing. The new concept also included pilot symbols, and time-slotted structure that has led to breakthrough features.
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OPTIMIZATION and COMPATIBILITY
Future proofing is a must and that means that the best and most advanced solution needs to be implemented. Utilizing existing infrastructure is a premium. From the operators' point of view, both together provide a cost effective and ultimate path for future services.
Along with optimization, a well-defined evolutionary path from existing digital 2nd generation technology (2G) to 3G services was paramount in the development of WCDMA. The most internationally deployed second-generation (2G) technology is GSM (Global System for Mobile) followed by D-AMPS (Digital-Advanced Mobile Phone System) and together, they account for over 80% of the global market. Already in 2G, the successive convergence between these two technologies – involving both the network infrastructure and mobile handset development (dual mode) – will bring about a true global service, unheard of before. This convergence will also fully draw from the coming Ericsson Worldphone that shows the way for future dual-mode telephones.
WCDMA was developed and optimized to support operators in these environments. The technology provides a level playing field to competing operators and that ultimately benefits the end user.
Backward compatibility is not an issue, as dual-mode phones will provide the service when required. 3rd generation systems must be able to realize the full potential of new services and backward compatibility would always hold it back.
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ROUTE TO 3G
The development of the mobile phone was the starting point for a new generation of wireless communication services involving voice, data, video and multimedia.
Market data speaks for itself: By the end of the year 2003, it is predicted that there will be some 830 million wireless subscribers and over 700 million Internet subscribers. This translates into a huge market potential for mobile Internet solutions, and mobile extensions to all our basic desktop applications and data files, independent of where we are.
The Internet paradigm can not be overlooked. There is sky-rocketing use of portable computers, notebooks, personal digital assistants (PDAs) – not to mention the advent of Web-enabled vehicles and digital photography with wireless access. Together with packet-switched wireless communications and multimedia, this in turn will drive an increase in the use of mobile communications.
First Generation
The first generation of cellular wireless communications was analog and progressively became available during the late 1970s and early 1980s.
The most successful analog systems have been based on the following standards, all of which are still in some demand today:
NMT (Nordic Mobile Telephone) was the first commercially available analog system, launched in 1979. It was initially introduced in Sweden, Norway,
Denmark and Finland and quickly spread to other parts of the world. The standard called for roaming and that was introduced between several countries.
AMPS (Advanced Mobile Phone Service) was launched in 1982. This has proved to be the most successful analog standard of all. AMPS networks can now be found on all continents.
TACS (Total Access Communications System) was originally specified for the UK and is based on AMPS. The original TACS specification was extended and is known as ETACS. TACS/ETACS has spread to other countries, particularly in the Asia Pacific region. Again, roaming was not a real possibility.
Second Generation
The introduction of digital wireless standards was borne out of the need to improve quality, coverage and capacity. Apart from enabling larger numbers of subscribers to be supported within a given frequency, plus new value-added services such as greater network security and cross-network roaming, digital standards made the movement towards PCS (Personal Communication Services) a lot easier.
The world's three most widely adopted digital wireless standards are all based on TDMA (Time Division Multiple Access) technology. They are:
GSM (Global System for Mobile communications) is the world's most widely adopted digital standard with more than 97.6 million subscribers, connected by over 200 networks in 110 countries (as of June 1998). It was also the first commercially available digital standard, introduced in 1992.
D-AMPS IS-136 is used by 13 million subscribers in 34 countries (as of June 1998). Although it is sometimes referred to as the "North American" digital standard, it is widely used in other regions particularly in Latin America and increasingly in the Asia Pacific and Eastern Europe. Overall, there are some 75 million users in D-AMPS/AMPS networks.
PDC (Personal Digital Communications) is the third-largest digital standard. Although it is only used in Japan, it accounts for approximately 33 million subscribers (as of June 1998).
A fourth digital standard currently in use is IS-95, based on narrowband CDMA (Code Division Multiple Access) technology. By mid 1998, it had 13 million subscribers, of which around 9 million were in South Korea.
ericsson.se
Thanks for the links Mika...DMG
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